Shop online for Full-Size Futon with Mattress Frame Bed Couch Sofa Cover Sleeper Dorm Furniture at $150.17. This Metal Arm Futon Frame with six-inch Mattress offers the best of both worlds. It has a stylish, contemporary design and brings functionality to any room in your home. It comes with retainer clips to prevent the mattress from sliding, along with retainer covers as a decorative touch. Double it as a comfortable bed when extra sleeping space is needed by converting quickly and easily from a sofa to a full-size sleeper.